Process of coating concrete pipes and hollow bodies with bituminous compositions



July 19, 1927. 3

R. ILLEMANN PROCESS OF COATING CONCRETE PIPES AND HOLLOW BODIES WITHBITUMINOUS COMPOSITIONS Filed Jan. 15, 1926 Invent or. Rillcrn unnb q aPatented July 19, 1927.

UNITED. STATES PATENT OFFICE.

ROBERT ELEMANN, OF GLASGOW, SCOTLAND. I

PROCESS OF COATING CONCRETE PIPES AND HOLLOW BODIE$ WITH BITUMINOUSCOMPOSITIONS.

Application flledlanuary 15, 1926.

It is known to manufacture concrete pipes and other hollow bodies from acomposition of cement and sand, or any other suitable aggregate, bycentrifugal action, i. e.-by a spin- 5 ning process, also to hand mouldor cast such pipes or bodies when the concrete is in a liquid orsemi-liquid condition.

My invention relates to a process and also to a composition of matter,forfuse in the rocess, whereby pipes or other hollow odies made ofconcrete'can be'efi'ectively coated or lined on the inner surface andalso, if required, on the outer surface with a bituminous-stone flourcoating.

The ractice usually adopted, up till now, for ma ing'concrete pipes and'linin them with a hot bituminous material is, rst, to spin the pipesfrom cement and any suita le aggregate and stack them away for set- 0tin and hardening, which takes several wee s, perhaps months, before thenecessary hardness is attained for the various water pressures which thepipes are required to resist when the ipes are in use.

l The main di culty and drawback up till now is that such "concreteipes, even if they are hard and it is intende to line them with an innercoating of a hot bituminous material, require a specially prepared innersurface characterized by keys and rooves made when the concrete is soft;or, 0t erwise, stone chips thrown in and partly embedded in the concreteso as to provide a rough inner surface on the pipe these chips serving,when i the concrete is set, as keys to give a gri or hold, to a certalnextent, for the hot b1- -tuminous substance.

I have found theforegoing practice is not only expensive but it is mostunreliable for l the reason that the dampness or moisture which is stillpresent in the hard concrete renders it impossible for the hotbituminous substance to adhere closely anduniformly on the innersurfaceof the concrete pipe.

i If it is sought to drive of the moisture from. the concrete pipe byheat and at the same time allow the inserted hot bituminous mass to runfreely in the pipe, then I find a fine dusty film is formed due to thecement being overheated or killed and this film of fine dust on theinner surface of the concrete pipe prevents the hot bituminous substanceadhering and uniformly uniting to Serial No. 81,473.

the concrete so that there is not an effective combination of theconcrete and the bituminous substance.

The object of my invention is to overcome these difliculties.

According to my invention I manufacture bituminously lined pipes orother hollow bodies of concrete by spinning a mass of concrete to formthe body, introducing a quantity of cold, aqueous, liquid bituminouscomposition into the body while the latteris still wet, continuing thespinning of the body to distribute the composition over the interiorsurface of the body and thereafter allowing or causing the concrete andthe bituminous composition to set simultaneously.

As a liquid bituminous composition I prefcrto use one whose preparationis hereinafter fully described.

In carrying out the invention I proceedas follows I prepare a cold,aqueous bituminous waterproofing composition, before the concrete pipeis made, by first making a creamy mixture of stone, reduced by grindincrushing, or otherwise, to a condition suc as flour, powder or dust,(hereinafter referred to as stone-flour) and water, and heating the sameto boilin' point and agitating it, and then adding bitumen in a liquidcondition by pouring same into the aforesaid boiling mixture the boilingbeing kept up and the mixture kept in a state of constant agitationuntil the mass is brought to the consistency 'of a stiff paste. I thenput the same amount of water into the mixture as has been evaporated bythe boiling, thinning it down further with water, according torequirements, and I continually stir and agitate the whole mass till itis cool. In making the com osition I may use the stone-flour and thebitumen in the pro ortion of about, for example, 48 lbs. by weight ofthe stone-flour fluid to 18 lbs. by weight of bitumen and thisproportion I ma vary according to the specific gravity of t e materialsand the bitumen used..

I wish it to be understood that when I use the.expression stone-flour inthe speciification and the claims appended I wish the same to cover andinclude stone reduced to a floury state; stony matter such as slate,

or sand, in a similar state (the sand being reduced to a state finerthan its natural state); and plumbago on graphite. \Vith thesesubstances no contraction of the composition occurs on drying, which isan important consideration.

I then proceed to spin the concrete pipe and as soon as the pipe is spunand made and while still wet and moist I immediately pour severalgallons of the cold, aqueous bituminous composition inside the concretepipe and continue the spinning thereby distributing the composition,specially prepared for the purpose, all over the inner surface of theconcrete pipe by centrifugal action and the composition will adhere andunite firmly with the wet concrete forming an even layer of bituminouscomposition on the inside thereof and rendering the pipe nonporous,waterproof and acid resisting and ready for use when dry.

After the spinning and lining of the con-- crete pipes with the saidbituminous composition is com leted they are stacked away to dry and baren, the bituminous composition and concrete bindin together and settingand hardening simul taneously.

For lining such pipes if required with a hot bituminous mixturecontaining no water, I proceed as follows ,I take one or more concretepipes previously treated as aforesaid with a coating of the beforedescribed mixture, when they are hard and dry, and place them back onthe spinning machine, or any other suitable revolving device, and Iclose up each end of the concrete pipes temporarily in such a manner asto prevent the hot bituminous composition from running out when pouredinto the concrete pipes.

It is advisable before the hot bituminous composition is poured in, towarm the interior of the pipe with hot air or similar means, in order toallow the hot bituminous composition to run freely and evenly andprevent the sudden chilling of the same.

After the required quantity of the hot bituminous composition has been sun and distributed evenly in each pi e, t e pipes can be quicklv cooleddown, rom the outside, with cold water applied by a water hose, or anyother suitab e means, the pi es being revolved all the time until the 0tbituminous composition inside the pipes is cold and hard and has firmlyadhered to the first applied bituminous composition so as.to form on theinside a hard black and glossy lining after-which the pipes are readyfor use.

The quantity and thickness of the hot bituminous coating is madeaccording to requirements and to the diameter of and the water pressureto be resisted by the concrete pipes.

Instead of natural bitumen in either of the bituminous compositionsmentioned, I

ma use pitch, tar, or similar bituminous an resinous matters or waxes.and which 1' wish to be covered by and included in the term bituminouscomposition.

To increase the internal strength of the whole concrete pipe I choose abitumen of most tenacious consistency and increase the melting point ofthe bitumen by adding thereto small quantities of sulphur flour, or,instead of sulphur, 1 may use stone-flour, and then add so much sand orcrushed stone, or any suitable aggregate, to the mixture, till it is ofa thick liquid consistency when hot. I may also increase the strengthand tenacity of the bitumen by placing a circular reinforcement or another suitable metallic reinforcement att to inner surface of thefinished concrete pipe and pour and spin the hot liquid bituminouscomposition on top of same combining and surrounding such reinforcementwith the bituminous composition and the concrete, thereby considerablyincreasing the strength of' the whole concrete pipe. The layer of thebituminous composition may be of the same thickness as or more than thethickness of the concrete.

The drawings annexed hereto show such a reinforced concrete pipe, Fig. 1being a longitudinal section partly broken away and Fig. 2 a crosssection, while Fig. 3 shows a piece of reinforcement. Fig. 4 is aperspective view of the pipe. In the drawings a is the concrete, 1) thebituminous-stone lining and c the reinforcement. This reinforcementpreferably consists of longitudinal members d consisting of flat metal,such as shown at c, Fig. 2 twisted into spiral formation, such as showrat f, same figure, these spirals f being secured to circumferentialmembers 9 (whicl may be plain round rods bent to shape] by welding atthe junctions. As will b seen at Fig. 2 the reinforcement is embeddet inand covered over by the linin The pJrOcedure hereinbefore re erred to aapplica 1e for concrete pipes would obvi ouslybe suitable for otherhollow bodie made of concrete.

The bituminous composition made as here inbefore described is not anemulsion, but i a composition formed by the microscopic par t-icles ofstone dust or flour, held in a stat of suspension in the water,constituting nu clei to and around which the bitumen whe it isintroduced clin in such manner as t form a multitude o bitumen-stoneglohule which, when the water is evaporated, autt matically adheretogether and during th boiling process form a wet pasty mass. I this wethe mass forms a bituminous-star composition to which water can be added2 desired for thinning purposes.

As the composition dries and sets the b tuminous globules bindthemselves togetht and seal and lose up the'pores left by tl tion whilethe concrete is still wet, continu ing the spinning of the body todistribute the bituminous composition over the interior surface of thebody and thereafter allowing the concrete and bituminous composition toset simultaneously.

2. A process of making bituminously lined pipes or other hollow bodiesof concrete con-' sisting in spinning a mass of concrete to form thebody, introducing into the body while the concrete is still wet aquantity of cold, aqueous bituminous composition composed of a mixtureof liquid bitumen with stone-flour and water, continuing the spinning ofthe body to distribute the bituminous composition over the interiorsurface of the body, and thereafter allowing the concrete and'bituminouscomposition to set simultaneousl and become dry and hard.

3. A process of makinv bituminously lined pipes or other hollow bo iesof concrete consisting in spinning a mass of concrete to form the body,mixing liquid bitumen with stone-flour and water in about the proportionof 18 pounds weight of bitumen to 48 pounds weight of stone-flour fluid,introducing a quantity of the said mixture into the concrete body whilethe latter is still wet, continuing the spinning of the body todistribute the bituminous mixture over the interior surface of the body,and thereafter allowing the concrete and the bituminous mixture to setsimultaneously.

4. A process of making bituminously lined pipes or other hollow bodiesof concrete consisting in s inning a mass of concrete to form the ha y,preparing a mixture of stoneflour and water, heating same to the boilingpoint, adding bitumen 1n 9. liquid condition, maintaining the mixture ina boilin condition until it assumes the form of a stiff paste, addingwater to the mass and agitating till cool, introducing a quantity of theaforesaid cold, aqueous bituminous mixture into the concrete body whilethe latter is still wet,

continuing the spinning of the body to distribute the mixture over itsinterior surface, and thereafter allowing the concrete and thebituminous mixture to set simultaneously and become dry and hard.

5. A process of making bituminously lined pipes or other hollow bodiesof concrete conisting in spinning a mass of concrete to form the body,introducing a quantity of cold,

aqueous, liquid bituminous composition while the concrete is still wet,continuing the spinning of the body to distribute the bituminouscomposition over the interior surface of the body, allowing the concreteand bituminous composition toset simultaneously, placing the hardenedbody on the spinning, machine, introducing a quantity of a hotnon-aqueous bituminous composition, spinning the body to distribute sameand thereafter cooling the body and lining, the lining applied coldserving as a key for the subsequent hot lining.

6. The process of makingbituminously lined pipes or other hollow bodiesof concrete consisting in s inning a mass of concrete to formlthe bo y,preparing a mixture of stone-flour and water, heating same to theboiling point, adding bitumen in a liquid condition, maintaining themixture in a boiling condition until it assumes the form of a stiffpaste, adding water to the mass and agitating till cool, introducing aquantity of the aforesaid cold, aqueous bituminous mixture into theconcrete body while the latter is still wet, continuing the spinning ofthe body to distribute the mixture over its interior surface, allowingthe concrete and the bituminous mixture therein to set simultaneously,again placing the hardened body on the spinning machine, introducing aquantity of a hot non-aqueous bituminous composition, spinning the bodyto distribute same and until the hot bituminous compo sition within thebody is cold and hard and has firmly adhered to the first appliedbituminous composition and forms a hard black and glossy lining.

7. A process of making bituminously lined pipes or other hollow bodiesof concrete consisting in spinning a mass of concrete-to form the body,introducing a quantity. of

cold, liquid, bituminous composition while the concrete is still wet,continuing the spinning of the body to distribute the cold bituminouscomposition over the interior surface of the body, allowing the concreteand the bituminous composition to set simultaneously, inserting acylindrical reinforcement into the body, again placin the hardened bodyon the spinning mac ine, intros ducing a quantity of a hot non-aqueousbituminous composition, spinning the body to distribute same over thereinforcement and until the hot bimninous composition within the body iscold and hard and has firmly adhered to the first ap lied bituminouscomosition and forms a I ard black and glossy ining.

8. A process of making bituminously lined pipes or other hollow bodiesof concrete consistin in spinning a mass of concrete to form the ody,preparing a mixture of stone- 'flour and water heatin same to theboiling point, adding bitumen m a liquid condition,

maintaining the mixture in a boiling condition until it assumes the formof a stiff paste, adding Water to the mass and agitating till cool,introducing a quantity of the aforesaid cold bituminous mixture into theconcrete body while the latter is still wet, continuing hard and hasfirmly adhered to the first applied bituminous composition and forms ahard black and glossy lining.

9. A bituminously lined pipe made by spinning a mass of concrete to formthe pipe, introducing a quantity of cold, aqueous, liquid bituminouscomposition while the concrete is still wet, continuing the spinning ofthe pipe to distribute the bituminous comosition over the interiorsurface of the pipe and thereafter allowing the concrete and bituminouscomposition to set simultaneously.

10. A bituminouslylined pipe made by spinning a mass of concrete to formthe pipe, introducing a quantity of cold and aqueous liquid. bituminouscomposition while the concrete is still wet, continuing the spinninghardened body on the spinning machine, in-' troducing a quantity of ahot nonaqueous bituminous composition, spinning the pipe to distributesame and thereafter cooling the pipe and lining, with water orotherwise, the lining applied cold serving as a key for the subsequenthot lining.

11. A bituminously lined pipe made by spinning a mass of concrete toform the pipe, introducing a quantity of cold aqueous and liquidbituminous composition while the concrete is still wet, continuing thespinning of the pipe to distribute the cold bituminous composition overthe interior surface of the pipe, allowing the concrete and the bituminous composition to set simultaneously, inserting a cylindrical.reinforcement into the pipe, again placing the hardened pipe on thespinning machine, introducing a quantity of a hot non-aqueous.bituminous composition, spinnin the pipe to distribute same over thereinforcement and until the hot bituminous composition within the bodyis cold and hard and has firmly adhered to the first applied bituminouscomposition and forms a hard black and lossy lining.

In testimony whereof aflix my signature.

ROBERT ILLEMANN.

